Driver instrument for use in a surgical application

Abstract

A surgical instrument for driving a threaded member into a substrate generally includes a drive shaft, a support member and a biasing member. The drive shaft is configured for releasable engagement with the threaded member. The drive shaft is axially coupled with the support member in a manner allowing relative axial displacement therebetween, with the drive shaft rotatably coupled with the support member. The biasing member is coupled between the support member and the drive shaft to transmit an axial force from the support member to the drive shaft as the threaded member is driven into the substrate, and with the axial force being limited as a distal end of the support member is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by the drive shaft to facilitate rotational disengagement of the drive shaft from the threaded member.

1. A surgical instrument for driving a threaded member into a substrate, comprising:
 a drive shaft extending generally along a longitudinal axis and including a distal end portion releasably and rotationally engaged with the threaded member; 
 a support member including a distal end positioned adjacent said distal end portion of said drive shaft, said drive shaft axially coupled with said support member to allow relative axial displacement therebetween, said drive shaft rotatably coupled with said support member by features that substantially prevent rotational displacement therebetween while allowing said relative axial displacement such that a rotational force applied to said support member is transmitted through said drive shaft to the threaded member, said features comprising a transverse projection positioned within an axially-extending groove, wherein said drive shaft includes an axially-extending shaft portion having a non-circular outer cross-section taken in a plane perpendicular to said longitudinal axis and positioned within an axially-extending passage portion defined by said support member; and 
 a biasing member engaged with portions of said support member and said drive shaft to transmit an axial force from said support member to said drive shaft, said biasing member exerting an axial biasing force onto said drive shaft in a distal direction which is transmitted through said drive shaft to the threaded member as the threaded member is driven into the substrate, said axial force being limited as said distal end of said support member is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by said drive shaft to said axial biasing force to facilitate rotational disengagement of said distal end portion of said drive shaft from the threaded member. 
 
   
   
     2. The surgical instrument of  claim 1 , wherein said distal end portion of said drive shaft includes a distal end and a passage extending from said distal end generally along said longitudinal axis, said passage being sized and shaped to receive a head portion of the threaded member therein. 
   
   
     3. The surgical instrument of  claim 1 , wherein said axial force exerted onto the threaded member by the drive shaft is limited to the amount of force transmitted through said biasing member and onto said drive shaft when said distal end of said support member is engaged against the surface adjacent the substrate. 
   
   
     4. The surgical instrument of  claim 3 , wherein said biasing member comprises a coil spring. 
   
   
     5. The surgical instrument of  claim 1 , wherein said support member comprises an outer sleeve defining an axial passage sized to receive said drive shaft therein, the surgical instrument further comprising a handle extending from said outer sleeve. 
   
   
     6. The surgical instrument of  claim 1 , wherein said biasing member comprises a coil spring. 
   
   
     7. The surgical instrument of  claim 1 , wherein the threaded member comprises a bone screw. 
   
   
     8. The surgical instrument of  claim 7 , wherein said bone screw is formed of a polymeric material. 
   
   
     9. The surgical instrument of  claim 1 , wherein the threaded member comprises a bone tap. 
   
   
     10. The surgical instrument of  claim 1 , wherein said axially-extending passage portion defined by said support member has a non-circular inner cross section. 
   
   
     11. The surgical instrument of  claim 10 , wherein said non-circular outer cross section of said axially-extending shaft portion has a first shape and said non-circular inner cross section of said axially-extending passage portion has a second shape corresponding to said first shape. 
   
   
     12. The surgical instrument of  claim 1 , wherein said axially-extending shaft portion includes a number of flatted areas defining said non-circular outer cross section. 
   
   
     13. The surgical instrument of  claim 12 , wherein said non-circular outer cross section of said axially-extending shaft portion has a generally triangular-shaped configuration. 
   
   
     14. A surgical instrument for driving a threaded member into a substrate, comprising:
 a drive shaft extending generally along a longitudinal axis and including a distal end portion releasably and rotationally engaged with the threaded member, wherein said distal end portion of said drive shaft includes a distal end and a passage extending from said distal end generally along said longitudinal axis, said passage being sized and shaped to receive a head portion of the threaded member therein, wherein said passage defines one or more tapered regions tapering outwardly toward said distal end to facilitate rotational disengagement of said drive shaft from the head portion of the threaded member; 
 a support member including a distal end positioned adjacent said distal end portion of said drive shaft, said drive shaft axially coupled with said support member to allow relative axial displacement therebetween, said drive shaft rotatably coupled with said support member by features that substantially prevent rotational displacement therebetween while allowing said relative axial displacement such that a rotational force applied to said support member is transmitted through said drive shaft to the threaded member, said features comprising a transverse projection positioned within an axially extending groove; and 
 a biasing member engaged with portions of said support member and said drive shaft to transmit an axial force from said support member to said drive shaft, said biasing member exerting an axial biasing force onto said drive shaft in a distal direction which is transmitted through said drive shaft to the threaded member as the threaded member is driven into the substrate, said axial force being limited as said distal end of said support member is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by said drive shaft to said axial biasing force to facilitate rotational disengagement of said distal end portion of said drive shaft from the threaded member. 
 
   
   
     15. The surgical instrument of  claim 14 , wherein said tapered regions open onto said distal end of said drive shaft. 
   
   
     16. The surgical instrument of  claim 14 , wherein said tapered regions cause said distal end of said drive shaft to walk off of the head portion of the threaded member upon application of a select amount of torque to said drive shaft. 
   
   
     17. A surgical instrument for driving a threaded member into a substrate, comprising:
 a drive shaft extending generally alone a longitudinal axis and including a distal end portion releasably and rotationally engaged with the threaded member, wherein said distal end portion of said drive shaft includes a distal end and a passage extending from said distal end generally along said longitudinal axis, said passage being sized and shaped to receive a head portion of the threaded member therein, wherein said distal end portion of said drive shaft defines one or more slots extending from said distal end generally along said longitudinal axis to facilitate flexible outward expansion of said distal end portion to releasably engage the head portion of the threaded member within said passage; 
 a support member including a distal end positioned adjacent said distal end portion of said drive shaft, said drive shaft axially coupled with said support member to allow relative axial displacement therebetween, said drive shaft rotatably coupled with said support member by features that substantially prevent rotational displacement therebetween while allowing said relative axial displacement such that a rotational force applied to said support member is transmitted through said drive shaft to the threaded member, said features comprising a transverse projection positioned within an axially extending groove; and 
 a biasing member engaged with portions of said support member and said drive shaft to transmit an axial force from said support member to said drive shaft, said biasing member exerting an axial biasing force onto said drive shaft in a distal direction which is transmitted through said drive shaft to the threaded member as the threaded member is driven into the substrate, said axial force being limited as said distal end of said support member is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by said drive shaft to said axial biasing force to facilitate rotational disengagement of said distal end portion of said drive shaft from the threaded member. 
 
   
   
     18. The surgical instrument of  claim 17 , wherein said distal end portion of said drive shaft defines two or more of said slots extending from said distal end generally along said longitudinal axis. 
   
   
     19. A surgical instrument for driving a threaded member into a substrate, comprising:
 a drive shaft extending generally alone a longitudinal axis and including a distal end portion releasably and rotationally engaged with the threaded member, wherein said distal end portion of said drive shaft includes a distal end and a passage extending from said distal end generally along said longitudinal axis, said passage being sized and shaped to receive a head portion of the threaded member therein, wherein said passage includes a receiver portion extending from said distal end generally along said longitudinal axis, said receiver portion including one or more transversely extending recessed areas sized and shaped to receive a corresponding number of transverse projections extending from the head portion of the threaded member; 
 a support member including a distal end positioned adjacent said distal end portion of said drive shaft, said drive shaft axially coupled with said support member to allow relative axial displacement therebetween, said drive shaft rotatably coupled with said support member by features that substantially prevent rotational displacement therebetween while allowing said relative axial displacement such that a rotational force applied to said support member is transmitted through said drive shaft to the threaded member, said features comprising a transverse projection positioned within an axially extending groove; and 
 a biasing member engaged with portions of said support member and said drive shaft to transmit an axial force from said support member to said drive shaft, said biasing member exerting an axial biasing force onto said drive shaft in a distal direction which is transmitted through said drive shaft to the threaded member as the threaded member is driven into the substrate, said axial force being limited as said distal end of said support member is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by said drive shaft to said axial biasing force to facilitate rotational disengagement of said distal end portion of said drive shaft from the threaded member. 
 
   
   
     20. The surgical instrument of  claim 19 , wherein said receiver portion of said passage and the head portion of the threaded member each have a splined configuration. 
   
   
     21. The surgical instrument of  claim 19 , wherein said distal end portion of said drive shaft defines one or more slots extending from said distal end generally along said longitudinal axis to facilitate flexible outward expansion of said distal end portion to releasably engage the head portion of the threaded member within said receiver portion of said passage, said slots being generally aligned with said recessed areas. 
   
   
     22. The surgical instrument of  claim 19 , wherein said receiver portion of said passage defines one or more tapered regions tapering outwardly toward said distal end to facilitate rotational disengagement of said drive shaft from the head portion of the threaded member, said tapered regions being positioned intermediate said recessed areas. 
   
   
     23. A surgical instrument for driving a threaded member into a substrate, comprising:
 a drive shaft extending generally along a longitudinal axis and including a distal end portion having a distal end and defining a first axial passage extending from said distal end, said first axial passage being sized and shaped to receive a head portion of the threaded member therein with said distal end portion releasably and rotationally engaged with the threaded member; 
 an outer sleeve defining a second axial passage sized to receive said drive shaft therein and including a distal end positioned adjacent said distal end portion of said drive shaft, said drive shaft coupled with said outer sleeve to allow relative axial displacement of said drive shaft along said second axial passage, said drive shaft rotatably coupled with said outer sleeve by features that substantially prevent rotational displacement therebetween while allowing said relative axial displacement such that a rotational force applied to said outer sleeve is transmitted through said drive shaft to the threaded member, said features comprising a transverse projection positioned within an axially-extending groove, wherein said drive shaft includes an axially-extending shaft portion having a non-circular outer cross-section taken in a plane perpendicular to said longitudinal axis and positioned within an axially-extending passage portion defined by said outer sleeve; and 
 a biasing member engaged with portions of said outer sleeve and said drive shaft to transmit an axial force from said outer sleeve to said drive shaft, said biasing member exerting an axial biasing force onto said drive shaft in a distal direction which is transmitted through said drive shaft to the threaded member as the threaded member is driven into the substrate, said axial force being limited as said distal end of said outer sleeve is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by said drive shaft to said axial biasing force to facilitate rotational disengagement of said distal end portion of said drive shaft from the head portion of the threaded member. 
 
   
   
     24. The surgical instrument of  claim 23 , wherein said axially-extending passage portion defined by said outer sleeve has a non-circular inner cross section. 
   
   
     25. The surgical instrument of  claim 24 , wherein said non-circular outer cross section of said axially-extending shaft portion has a first shape and said non-circular inner cross section of said axially-extending passage portion has a second shape corresponding to said first shape. 
   
   
     26. The surgical instrument of  claim 23 , wherein said axially-extending shaft portion includes a number of flatted areas defining said non-circular outer cross section. 
   
   
     27. The surgical instrument of  claim 26 , wherein said non-circular outer cross section of said axially-extending shaft portion has a generally triangular-shaped configuration. 
   
   
     28. A surgical instrument for driving a threaded member into a substrate, comprising:
 a drive shaft extending generally along a longitudinal axis and including a distal end portion having a distal end and defining a first axial passage extending from said distal end, said first axial passage being sized and shaped to receive a head portion of the threaded member therein with said distal end portion releasably and rotationally engaged with the threaded member, wherein said first axial passage defines one or more tapered regions tapering outwardly toward said distal end of said drive shaft to facilitate rotational disengagement of said distal end portion of said drive shaft from the head portion of the threaded member; 
 an outer sleeve defining a second axial passage sized to receive said drive shaft therein and including a distal end positioned adjacent said distal end portion of said drive shaft, said drive shaft coupled with said outer sleeve to allow relative axial displacement of said drive shaft along said second axial passage, said drive shaft rotatably coupled with said outer sleeve by features that substantially prevent rotational displacement therebetween while allowing said relative axial displacement such that a rotational force applied to said outer sleeve is transmitted through said drive shaft to the threaded member, said features comprising a transverse projection positioned within an axially extending groove; and 
 a biasing member engaged with portions of said outer sleeve and said drive shaft to transmit an axial force from said outer sleeve to said drive shaft, said biasing member exerting an axial biasing force onto said drive shaft in a distal direction which is transmitted through said drive shaft to the threaded member as the threaded member is driven into the substrate, said axial force being limited as said distal end of said outer sleeve is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by said drive shaft to said axial biasing force to facilitate rotational disengagement of said distal end portion of said drive shaft from the head portion of the threaded member. 
 
   
   
     29. The surgical instrument of  claim 28 , wherein said tapered regions open onto said distal end of said drive shaft. 
   
   
     30. The surgical instrument of  claim 28 , wherein said tapered regions cause said distal end of said drive shaft to walk off of the head portion of the threaded member upon application of a select amount of torque to said drive shaft. 
   
   
     31. The surgical instrument of  claim 28 , wherein said one or more tapered regions include distally-facing surfaces tapering outwardly toward said distal end in a radial direction relative to said longitudinal axis to facilitate said rotational disengagement of said drive shaft from said head portion of the threaded member. 
   
   
     32. A surgical instrument for driving a threaded member into a substrate, comprising:
 a drive shaft extending generally along a longitudinal axis and including a distal end portion having a distal end and defining a first axial passage extending from said distal end, said first axial passage being sized and shaped to receive a head portion of the threaded member therein with said distal end portion releasably and rotationally engaged with the threaded member, wherein said distal end portion of said drive shaft defines one or more slots extending from said distal end generally along said longitudinal axis to facilitate flexible outward expansion of said distal end portion to releasably engage the head portion of the threaded member within said first axial passage; 
 an outer sleeve defining a second axial passage sized to receive said drive shaft therein and including a distal end positioned adjacent said distal end portion of said drive shaft, said drive shaft coupled with said outer sleeve to allow relative axial displacement of said drive shaft along said second axial passage, said drive shaft rotatably coupled with said outer sleeve by features that substantially prevent rotational displacement therebetween while allowing said relative axial displacement such that a rotational force applied to said outer sleeve is transmitted through said drive shaft to the threaded member, said features comprising a transverse projection positioned within an axially extending groove; and 
 a biasing member engaged with portions of said outer sleeve and said drive shaft to transmit an axial force from said outer sleeve to said drive shaft, said biasing member exerting an axial biasing force onto said drive shaft in a distal direction which is transmitted through said drive shaft to the threaded member as the threaded member is driven into the substrate, said axial force being limited as said distal end of said outer sleeve is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by said drive shaft to said axial biasing force to facilitate rotational disengagement of said distal end portion of said drive shaft from the head portion of the threaded member. 
 
   
   
     33. A surgical instrument for driving a threaded member into a substrate, comprising:
 a drive shaft extending generally along a longitudinal axis and including a distal end portion having a distal end and defining a first axial passage extending from said distal end, said first axial passage being sized and shaped to receive a head portion of the threaded member therein with said distal end portion releasably and rotationally engaged with the threaded member, wherein said first axial passage includes a receiver portion extending from said distal end generally along said longitudinal axis, said receiver portion including one or more transversely extending recessed areas sized and shaped to receive a corresponding number of transverse projections extending from the head portion of the threaded member; 
 an outer sleeve defining a second axial passage sized to receive said drive shaft therein and including a distal end positioned adjacent said distal end portion of said drive shaft, said drive shaft coupled with said outer sleeve to allow relative axial displacement of said drive shaft along said second axial passage, said drive shaft rotatably coupled with said outer sleeve by features that substantially prevent rotational displacement therebetween while allowing said relative axial displacement such that a rotational force applied to said outer sleeve is transmitted through said drive shaft to the threaded member, said features comprising a transverse projection positioned within an axially extending groove; and 
 a biasing member engaged with portions of said outer sleeve and said drive shaft to transmit an axial force from said outer sleeve to said drive shaft, said biasing member exerting an axial biasing force onto said drive shaft in a distal direction which is transmitted through said drive shaft to the threaded member as the threaded member is driven into the substrate, said axial force being limited as said distal end of said outer sleeve is engaged against a surface adjacent the substrate to correspondingly limit an axial force exerted onto the threaded member by said drive shaft to said axial biasing force to facilitate rotational disengagement of said distal end portion of said drive shaft from the head portion of the threaded member. 
 
   
   
     34. The surgical instrument of  claim 33 , wherein said receiver portion of said passage and the head portion of the threaded member each have a splined configuration. 
   
   
     35. The surgical instrument of  claim 33 , wherein said distal end portion of said drive shaft defines one or more slots extending from said distal end generally along said longitudinal axis to facilitate flexible outward expansion of said distal end portion to releasably engage the head portion of the threaded member within said receiver portion of said passage, said slots being generally aligned with said recessed areas. 
   
   
     36. The surgical instrument of  claim 33 , wherein said receiver portion of said passage defines one or more tapered regions tapering outwardly toward said distal end to facilitate rotational disengagement of said drive shaft from the head portion of the threaded member, said tapered regions being positioned intermediate said recessed areas.